New materials for large-area position-sensitive detectors

Large-area thin-him position-sensitive detectors (TFPSDs) using the hydrogenated amorphous silicon (a-Si:H) technology are presented. The detection accuracy of these devices (lengths of about 80 mm) is better than +/- 0.5% of the value of the full scale of the sensor, the spatial resolution is better than +/- 20 mu m, the non-linearities measured are below +/- 2% and the frequency response is in the range of a few kilohertz, compatible with the sampling frequency of most electromechanical assembling/control systems. The obtained results are quite promising regarding the application of these sensors to a wide variety of optical inspection systems. (C) 1998 Elsevier Science S.A, All rights reserved.